Allocate the full mSATA cache capacity to Smart Response
This how-to is intended for any XPS 15s purchased with a spinning hard drive and the 32GB mSATA cache, and explains how to delete the existing Intel Rapid Start partition to increase the caching capacity of Intel Smart Response and thus overall system performance. By default, the mSATA cache is configured with an 8 GB Intel Rapid Start partition with the remainder of its capacity used as a cache for Intel Smart Response. On systems with 16 GB of RAM: The 8 GB Rapid Start partition is completely wasted because Rapid Start requires a partition equal in size to the amount of physical memory in the system in order to function, and thus there is no downside to eliminating the Rapid Start partition in favor of increased Smart Response caching capacity. However, it's worth noting that this quirk of systems with 16 GB of RAM having Smart Response but not (functional) Rapid Start means that these systems will likely cold boot faster than they will resume from hibernation. The reason is that Smart Response caches boot files on the mSATA cache, but without Rapid Start, the hibernation file is written to the spinning disk, which takes much longer to read during resume. On systems with 8 GB of RAM: Intel Rapid Start will decrease your resume from hibernation times because it will ensure that hibernation files are always written to the SSD cache rather than the spinning hard drive (where the default Windows hibernation would place it), but Rapid Start has also been known to cause other problems documented here. Therefore, you should consider following the instructions below if any of the following apply to you: - You have a system with 16 GB of RAM (technically you could disable Smart Response to fix Rapid Start on such a system, but then you'd be sacrificing significant overall system performance purely to gain faster entry and exit from hibernation times.) - You have a system with 8 GB of RAM (and thus functional Intel Rapid Start), but you're experiencing problems with resuming from sleep/hibernation and want to test whether Rapid Start is the culprit. - You have a system with 8 GB of RAM and either don't care about resume from hibernation times at all or would prefer better overall system performance over faster resume times. Step-by-step #Open the Intel Rapid Start application and switch Rapid Start to Off. (Optionally, if you wish to re-enable regular Windows hibernation at this point, open a Command Prompt with administrative privileges and enter "powercfg -h on".) #Open Computer Management and select Disk Management. In the bottom half of the main area of the window where partition maps are shown as blocks with each row corresponding to a disk, look for a disk with a single partition of 8-8.02 GB (it will either be labeled a Primary Partition or an OEM partition.) This is the Rapid Start hibernation partition. Take a note of the disk number that has this partition, which will be shown to the left of the partition. (NOTE: If you don't see this disk with a solitary 8-8.02 GB partition, it likely means that Rapid Start is already disabled and the entire mSATA cache has already been dedicated to Smart Response, in which case skip these steps and go to this article to learn about a way to further improve performance by changing the acceleration mode.) #Open the Intel Rapid Storage application. #On the Performance tab (maybe called Acceleration), disable acceleration (aka Smart Response). This is temporary. #Restart. Slow performance at this point would be normal because Smart Response is no longer active. #Go back to the Intel Rapid Storage application, select the Performance/Acceleration tab, and click Remove Volume. #Open a Command Prompt and type "diskpart". Click through the UAC prompt if you see one. Then enter the following commands in diskpart: ##select disk X (where X is the number of the disk containing the Rapid Start partition you found in Step 2) ##list partition (there should only be one, but just to be sure, take a note of the partition number whose capacity matches the partition you found in Step 2) ##select partition X (where X is the partition number you just determined) ##delete partition override #Go back to Computer Management > Disk Management and confirm that that disk now shows unallocated space rather than an actual partition. #Restart again. #Open Intel Rapid Storage. Go to the Performance/Acceleration tab and enable acceleration again. This time you'll be able to allocate the entire mSATA cache for Smart Response. For information on the two available acceleration modes (Enhanced and Maximized), see here.